1. Technical Field
The invention includes embodiments that relate to a sealing material and seal ring for an energy storage device. The invention includes embodiments that relate to a method of sealing an electrochemical cell.
2. Discussion of Related Art
Development work has been undertaken on high temperature rechargeable batteries using sodium for the negative electrodes. The liquid sodium negative electrode is separated from a positive electrode by a sodium-ion conducting solid electrolyte. Suitable material includes beta alumina and beta” alumina, known as beta alumina separator electrolyte (BASE). Some electrochemical cells have a metallic casing. Interior parts of the battery and the metallic casing may seal to interior parts of the battery. The ceramic parts of the cell can be joined via a seal glass. The seal glass may have undesirable characteristics associated with its use. Metallic parts can be joined by welding or thermal compression bonding. Bonded parts formed from dissimilar materials in a high temperature cell may crack resulting due to thermal stress caused by mismatch in the coefficient of thermal expansion. The coefficient of thermal expansion for a ceramic part and a metal part can be very dissimilar. The bond may have a limited life, and bond failure may cause cell failure.
It may be desirable to have a sealing material for an energy storage device that differs from those sealing materials that are currently available. It may be desirable to have a seal structure that differs from those seal structures that are currently available. It may be desirable to have a method of sealing an energy storage device that differs from those methods that are currently available.